#include  <cstdio>

int fn(int n)
{
	int res = 1;
	for( int i = n; i > 0 ; --i )
		res *= i;
	return res;
}

int main(int argc, char *argv[])
{
	printf("n e\n- -----------\n0 1\n1 2\n2 2.5\n");

	double sum = 2.5;
	int n = 3;
	while(n < 10)
	{
		sum += 1.0L/fn(n);
		printf("%d %.9lf\n",n++,sum);
	}
}
